Study of Nonlinear Electric Field Effects in Tetramethyltetraselenefulvalene Hexafluorophosphate [(TMTSF)2PF6]

Detailed field- and frequency-dependent conductivity measurements are reported in ${\mathrm{}\left(\mathrm{TMTSF}\right)\mathrm{}}_2$P${\mathrm{F}}_6$. No threshold field and a small dielectric constant are found, implying the absence of restoring forces. No evidence is found for wide- or narrow-band noise in the nonlinear regime. This, together with the preliminary observation of a high mobility, suggests that single-particle effects are largely responsible for the nonlinear conductivity below the transition.